Reductive Cross-Coupling to Access C-N Bond from Aryl Halides and Diazoesters under Dual Nickel/Photoredox-Catalyzed Conditions

The couplings to construct aryl C–N bonds typically focus on neutral-redox conditions. Herein, a reductive cross-coupling reaction to access C(sp2)–N bonds via dual Ni/photoredox-catalyzed systems has been reported for the first time. By utilizing the easily available diazo compounds as a nitrogen source, aryl hydrazones can be readily obtained under exceptionally mild conditions (visible light, ambient temperature, and no strong base). This method accommodates a broad scope of many functional groups and provides a novel route to deliver this type of product which can be further transformed into several kinds of nitrogen-containing heterocycles.